1. Field of the Invention
The invention relates to a polishing slurry composition, particularly to a polishing slurry composition used in chemical mechanical polishing (CMP) to remove metal thin films and effectively control the extent of dishing.
2. Description of Related Art
Chemical mechanical polishing is the process of removing material (e.g. deposited thin films) by applying a combination of chemical reactions and mechanical polishing. Chemical mechanical polishing can make the surface of a material smoother and more even. Chemical mechanical polishing is often used to remove the excess metal film in a typical manufacturing process of semiconductors, so as to form a metal interconnection. For example, because of the development of Damascene manufacturing process, chemical mechanical polishing becomes widely used in the manufacturing process of the copper interconnection.
In the manufacturing process of chemical mechanical polishing, the wafer is typically fixed to a carrier and pressed against a polishing pad. At the same time, a polishing slurry is conveyed to the surface of the polishing pad. The polishing slurry contains large amounts of polishing particles and various kinds of chemicals which react with a material to be polished, so as to dissolve the material or to form compounds, and the compounds are removed by the polishing particles due to mechanical friction as the polishing pad spins or moves.
Even though chemical mechanical polishing is widely employed in the manufacturing process of semiconductors, it still creates some defects such as scratching, corrosion and dishing. These problems remain to be solved.